Conventionally, projector screens are basically white background screens that can reflect or Scatter almost all part of light in the visible wavelength region. In this case, since such a screen also scatters or reflects external light irrelevant to images if it intrudes onto the screen, images deteriorate in contrast. Therefore, projection is usually carried out in a dark room.
However, even during projection in a dark room, any light filtering from the exterior or any light irrelevant to images inside the dark room deteriorates the contrast of the images, and raises the luminance level of black-displaying portions.
In displays such as CRT or liquid crystal displays that are widely used, since light of each primary color has a wide spectral full width at half maximum (FWHM), the color reproduction range on a chromaticity diagram is narrow, and it is difficult to represent pure colors. Also in liquid crystal or CRT projector-type displays, light forming an image scattered or reflected from a screen similarly has a wide spectral full width at half maximum, the color reproduction range on a chromaticity diagram is narrow, and it is difficult to represent pure colors.
It is therefore an object of the invention is to provide a screen that can presents clean images in which black-displaying portions are lowered in luminance level even upon intrusion of any external light irrelevant to images, without deteriorating the contrast of images, and also to provide a manufacturing method of the screen and an image display system using the screen.
A further object of the invention is to provide a screen not deteriorating the contrast of images even under an ordinary fluorescent lamp or in the open air and therefore not requiring projection in a dark room, and also to provide a manufacturing method of the screen and an image display system using the screen.
A still further object of the invention is to provide a screen that can maintain a high contrast by efficiently, selectively reflecting light of images exclusively and cutting light of other wavelengths and can simultaneously lower the luminance level of black-displaying portions in the case where the full width at half maximum of emission spectrum of a semiconductor laser or a light emitting diode (LED) is narrow and images are formed by projecting light excellent in color purity, and to provide a manufacturing method of the screen and an image display system using the screen.
A yet further object of the invention is to provide a screen that can ensure a wide color reproduction range on a chromaticity diagram even when projecting light from a display like a liquid crystal projector, for example, having a wide full width at half maximum of the spectrum of each primary color, and can represent pure colors, and to provide a manufacturing method of the screen and an image display system using the screen.